87 results about "Polysialic acid" patented technology

Methods of making ligand-decorated polymer conjugates of therapeutic glycoproteins are described. Improved targeting of glycoproteins to specific tissues is achieved by masking the natural carbohydrate and other surface determinants with high molecular weight polymers, such as, e.g., PEG, polysialic acid, etc., which in turn are decorated with target-specific ligands. In some embodiments, acid-labile linkages in such conjugates or rapidly degradable masking groups allow for the intracellular release of the polymer from the glycoprotein, for example, under conditions found in lysosomes.

The present invention relates to a proteinaceous construct comprising plasmatic or recombinant factor VIIa (FVIIa) or biologically active derivatives thereof, which are bound to a carbohydrate moiety comprising 1-4 sialic acid units, wherein the in vivo half-life of the proteinaceous construct is substantially prolonged in the blood of a mammal, as compared to the in vivo half-life of a FVIIa molecule not bound to a carbohydrate moiety. The invention also provides a method for controlling bleeding in a mammal having a bleeding disorder due to functional defects or deficiencies of FVIIa, FVIII, or FIX. The invention also provides a method for controlling bleeding in a mammal during surgery or trauma.

The invention discloses a fermentation production method of sialic acid and belongs to the technical field of bioengineering. The method comprises the following steps: adding a seed liquid into a fermentation tank containing a sterilizing fermentation culture medium; continuously fermenting to produce fermentation liquid containing polysialic acid in a way of replenishing feeding liquid and a hydrogen dioxide solution; then carrying out centrifugal separation, ethanol precipitation and filtration to obtain refined polysialic acid; then, carrying out acidolysis and crystallization on the polysialic acid; and finally, washing and freeze-drying to obtain sialic acid powder. The output of the polysialic acid produced by the method provided by the invention can reach 12.96g/L, the already reported maximum content of the polysialic acid is improved by 87.28%, the hydrolysis rate of polysialic acid is 95%, the content of purified sialic acid reaches 10.01g/L and the purity reaches 94.80%. The method is suitable for industrial promotion and application.

Novel bactericidal antibodies against Neisseria meningitidis serogroup B (“MenB”) are disclosed. The antibodies either do not cross-react or minimally cross-react with host tissue polysialic acid and hence pose minimal risk of autoimmune activity. The antibodies are used to identify molecular mimetics of unique epitopes found on MenB or E. coli K1. Examples of such peptide mimetics are described that elicit serum antibody capable of activating complement-mediated bacteriolysis of MenB. Vaccine compositions containing such mimetics can be used to prevent MenB or E. coli K1 disease without the risk of evoking autoantibody.

Disclosed are methods, compositions, devices, and kits for the isolation of brain-specific exosomes. Specifically, methods, compositions, devices, and Unbound kits comprising an isolated brain-specific extracellular vesicle or exosome joined to a first binding agent that is specific for tau, β-amyloid, SlOO β, neuron-specific enolase, glycoprotein A2B5, CD133, NQ01, synaptophysin, neuronal nuclei, MAB 1569, polysialic acid-neural cell adhesion molecule (PSA-NCAM), or neurogenic differentiation 1 (NeuroD or Beta2), or glycosylated or phosphorylated forms of these molecules, are provided.

The invention provides a method for producing poly-N-acetylneuraminic acid by fermentation of escherichia coli CGMCC NO.5585 and a purification method of the poly-N-acetylneuraminic acid. The high-purity poly-N-acetylneuraminic acid without endotoxins is further obtained and can meet the production requirements of foods, cosmetics and medicaments. According to the methods provided by the invention, the fermentation raw material uses cheap glucose to replace more expensive sorbitol, the yield of 5-6g/L can be still obtained during the fermentation stage, and the methods are particularly suitable for industrial fermentation production of PSA (polysialic acid); and finally, through the follow-up purification step, the high-purity PSA with the polymerization degree of at least above 70000Da, the purity of at least more than 95% (HPLC(high performance liquid chromatography)) and the yield of 4-4.5g/L can be obtained.

The invention relates to a fusion protein comprising a bifunctional sialytransferase and a poly-sialytransferase and methods to use the fusion proteins for production of poly-sialylated end products, e.g. oligosaccharides and glycoproteins.

The invention belongs to the field of medicine preparations, and particularly relates to polysialic acid lipid grafted derivatives, a preparing method thereof and applications of the derivatives, particularly applications for preparation and modification of microparticle preparations. Sialic acid units in the polysialic acid are connected through alpha-2,8-glucosidic bonds, and lipid segments and hydroxy in the sialic acid units are connected through ester bonds. A structural formula is shown in the description, wherein SA is a sialic acid unit, x is the number of the lipid segments grafted in the polysialic acid molecule, m is the number of the sialic acid units in the polysialic acid molecule, the m is not more than 100 and not less than 1, the x is not more than 30 and not less than 1, x/m is 5-30%, R-CO- is derived from R-COOH, and the R-COOH is a lipid compound containing carboxyl. Immunogenicity of microparticle preparations prepared or modified by the compounds is extremely low and the microparticle preparations have excellent in-vivo pharmacokinetic properties.

The invention belongs to the technical field of high molecular materials, and in particular relates to a new polysialic acid active derivative with a double bond structure and a preparation method thereof and application of the derivative to the medicine preparation. The derivative can be widely applied to the modification of amino-contained biological functional molecules, in particular to macromolecules such as proteins and polypeptides, and the improvement of medicinal solubility, stability and immunogenicity, thereby prolonging the half life of the medicines and improving the efficacy.

The invention relates to a method for promoting fermentation of Escherichia coli to produce polysialic acid, and relates to the fermentation engineering field. The method for promoting fermentation ofEscherichia coli to produce polysialic acid comprises the following steps: inoculating Escherichia coli into fermentation medium for culture and fermentation, and separating to obtain polysialic acid; when fermenting, controlling the fermentation of the temperature between 0-48 hours to be 40-42 DEG C, the fermentation temperature after 48 hours to be 36 DEG C to 38 DEG C. The method for promoting the fermentation of Escherichia coli to produce polysialic acid can effectively improve the fermentation level, synthesis efficiency and carbon source conversion efficiency of polysialic acid.

The invention relates to probiotics microcapsule bacterial powder and a preparation method and application thereof. The probiotics microcapsule bacterial powder is prepared from core materials and wall materials, the core materials comprise probiotics, and the wall materials comprise polysialic acid. The polysialic acid creatively serves as the wall materials of microcapsules, the probiotics serves as the core materials of the microcapsules, thus the polysialic acid and the probiotics can exert respective physiological functions and can also synergistically act, a probiotics preparation can exert better properties, and the bacterial survival rate of the probiotics is remarkably increased; the activity of the probiotics can also be improved; and meanwhile the probiotics can be smoothly colonized in the intestinal tract, and the physiological effect is exerted better.

Peptides that mimic the antigenic features of non human-cross-reactive protective epitopes of the MenB CP and nucleic acids encoding the peptide mimetics are disclosed. Antibodies elicited by these peptides do not bind to polysialic acid in host tissue and thus provide a safe and efficacious method for the treatment and/or prevention of Meningitis B.

Gel nanoparticles for encapsulating and delivering a pharmaceutical compound to a patient. The nanoparticles are formed from N-trimethyl chitosan and polysialic acid, preferably in the presence of sodium tripolyphosphate. A ratio of polysialic acid to N-trimethyl chitosan of about 0.5 to 1 produces nanoparticles having diameter of about 100 nm (plus or minus 25 nm) and a zero potential above 30 milivolts that can stability contain a pharmaceutical compound, such as methotrexate, for delivery to a patient.

The invention provides a preparation method and application of polyethylene glycol-polysialic acid block copolymers, which belong to the technical field of polymer materials. The copolymers are formed by connecting activated polysialic acid with different-base bifunctional polyethylene glycol, and are expressed as X-PEG-F-PSA, wherein X is one of active groups of different-base bifunctional PEG and is used to be connected with the active groups on protein or polypeptide; F is another active group of the different-base bifunctional PEG and is used to be connected with activated polysialic acid PSA; the block copolymers X-PEG-F-PSA are connected with Protein so as to form Protein-PEG-PSA products. The products can be widely used to modify amino-containing biological functional molecules, particularly protein or polypeptide and other macromolecules, and by utilizing the strong hydration performance of PEG and the immunogenicity of PSA, low-molecular-weight PEG and PSA are connected to modify various protein or polypeptide medicaments in order to improve the dissolvability, stability and immunogenicity of the medicaments, prolong the half-life period of the medicaments and improve therapeutic effects..

The invention discloses a preparation method of polysialic acid-hyaluronic acid composite gel, an obtained product and an application. The preparation method comprises steps as follows: in an alkaline aqueous solution environment, polysialic acid is linked with a crosslinking agent, and activated polysialic acid is obtained; the activated polysialic acid is added to a hyaluronic acid solution, so that the polysialic acid is grafted on the hyaluronic acid in an acid environment, and the product is obtained. The reaction process is controllable, few side reactions exist, the obtained product has excellent biocompatibility of the hyaluronic acid and non-immunogenicity of the polysialic acid, can be applied to embedded slow-release of polypeptide or protein drugs and can also applied to coating of crosslinked hyaluronic acid gel particles for injection, the postoperative inflammatory reaction is reduced, skin redness and swelling are relieved, pain of users is relieved, besides, the product stability can be improved, the degradation time can be prolonged, and the half-life period can be prolonged.

The invention discloses a method for preparing N-acetvlneuraminic acid through integrated polysialic acid separation and purification. The method comprises the steps that feed liquid containing the polysialic acid serves as a raw material and is hydrolyzed with oxalic acid, calcium, magnesium and other ions are precipitated with oxalic acid, protein impurities are precipitated with ethyl alcohol,activated carbon decoloration is conducted, and precipitates, such as calcium salt and magnesium salt and impurities, such as proteins, are removed through filtration of an activated carbon carrier; the high-purity N-acetvlneuraminic acid is obtained through clear liquid concentration, acidification, crystallization and drying. By testing, the purity of the N-acetvlneuraminic acid is at least 98%,and the N-acetvlneuraminic acid can meet requirements of the fields, such as foods, health care, medicines and cosmetics. The method is simple, easy to operate and especially suitable for productionof the N-acetvlneuraminic acid through industrial fermentation.

The invention relates to the technical field of bioengineering, and particularly discloses a preparation method of polysialic acid and a polysialic acid product. The method comprises the following steps: S1, strain fermentation; S2, filtering through a membrane to remove thalli: filtering the fermentation liquid through a ceramic membrane to obtain membrane clear liquid; S3, heat treatment: adding alkali liquor into the membrane clear liquid, adjusting the pH value of the membrane clear liquid, and performing water bath heat treatment to obtain heat treatment liquid; S4, filtering and precipitating: adding diatomite into the heat treatment liquid, then carrying out filter pressing, taking filtrate I, carrying out ultrafiltration through an organic membrane, taking filtrate II, and adding absolute ethyl alcohol to obtain crude polysialic acid precipitate; S5, dissolving and decolorizing; and S6, concentrating and centrifuging. The preparation method is simple, thalli are removed more thoroughly, redundant salt and small molecule impurities are removed, the protein removal effect is obvious under the alkaline heating condition, the addition of a complexing agent is reduced, and the method is safe and effective.

The invention relates to a method for preparing oligomeric sialic acid, belonging to the technical field of biological engineering. The method comprises the following steps: hydrolyzing alpha2-8 connected polysialic acid under a mild condition, separating by using an ultrafiltration membrane, collecting the oligomeric sialic acid with the degree of polymerization of 2-10, desalting, concentratingby using a concentration membrane separation system, freezing and drying to obtain the product which is the oligomeric sialic acid. The oligomeric sialic acid can be used as a functional nutritional additive and can be applied to the technical fields of cosmetics, medicaments and other biological medicaments.